But another crisis could be brewing for Google as advertisers wise up to the fact that their ads aren’t always being displayed alongside relevant content.

As detailed by AdAge’s Jack Neff, one advertiser reviewed 1,000 YouTube videos its ads had been displayed with and came to the conclusion: “A lot of inventory was going to the wrong place.”

What does that mean in practice?

Zefyr, a VideoID technology provider, performs audits for advertisers and Andrew Serby, the company’s director of marketing, gave the example of alcohol marketers’ ads “showing up in front of ‘Minecraft’ videos, Peppa Pig and all this problematic content where the only possible consumer is a kid.”

Serby further explained:

We’ve looked at several campaigns where the target is a 25-year-old male or a 35-year-old woman, and no matter what, they’re running against Peppa Pig videos, because the algorithm goes to where the eyeballs are, and younger people aren’t skipping ads, and if there’s a shared device and you’re demo targeting, mom hands the kid an iPad and they see it.

Oops. For all of Google’s efforts to build tech that can track consumers across devices, it’s targeting capabilities are clearly falling short in this type of shared device scenario.

John Snyder, CEO of Grapeshot, a “context marketing engine”, suggests that this is because Google is ignoring the relevance problem. “They let these things happen because they’re a media company, and they want to sell as many ads as possible. Basically, the tools are there. They’re just not using them,” he told AdAge.

Grapeshot’s tool, which is used by brands like Unilever, Johnson & Johnson and Chase, as well as media agencies including Group M and Ogilvy, has access to Facebook inventory but not YouTube inventory.

So what can advertisers do?

They can gain access to theoretically more relevant inventory through the Google Preferred program, which “aggregates YouTube’s top content…into easy-to-buy packages for brand advertisers.” These packages offer access to 12 “lineups” that fit into categories like Beauty and Fashion and Entertainment and Pop Culture.

But as AdAge’s Neff notes, Google Preferred is already crowded and the costs of participation are hefty.

“Preferred inventory is scarcer and pricier, subject either to category exclusives or more clutter from competitors, and leaves out lots of high-quality content,” he explained, while also noting that Google Preferred, at one point, even included inventory from PewDiePie, the YouTube star whose offensive videos sparked the brand safety backlash.

Ultimately, there are few easy answers. Nobody in the ecosystem is realistically going to pay human reviewers to sort through millions upon millions of videos, screening them for relevance. Brand safety is a big enough challenge.

More likely, advertisers will have to come to grips with the fact that there will always be a conflict between reach and relevance, meaning being able to buy millions or billions of impressions in an automated or semi-automated fashion while ensuring relevance is little more than a pipe dream.

Instead, advertisers will need to accept that greater relevance will come at a higher cost through programs like Google Preferred, as well as private programmatic exchanges (programmatic direct).

They will also have to look at their investments in alternative ad formats, such as native ads, which not only promise greater levels of brand safety but could also be easier to control vis-à-vis relevance.